The applicants proposed to develop a network of microminiature, integrated, three degree of freedom joint orientation and inclination tracking modules (3DM's), designed for use with functional electrical stimulation (FES) systems. Solid state accelerometers and magnetometers will detect Earth's gravitational and magnetic field vectors, and an embedded processor (in each 3DM) will resolve pitch, yaw and roll orientations as well as provide digital filtering. Advantages of 3DM's include: portability (since Earth's fields are always available), no moving parts, no linkages cross the user's joints, mounting may be done by elastic straps, small size, low power, recalibration after mounting is not required, and 3DM's can be produced at low cost. As many as 32 tracking nodes may be placed on the network, with orientation from each node updated at a 60 Hz rate. Calibrations will be performed on the factory bench, and these coefficients will reside in the modules' on board memory. Frequency response and total range of motion will be maximized through embedded software development and appropriate analog and digital filtering. The systems will be tested to insure target specifications are met, and an open software architecture will allow researchers to tailor 3DM parameters for their specific FES applications. PROPOSED COMMERCIAL APPLICATION: Miniature orientation devices are useful for a variety of applications, including FES. Computer input can pointing devices, camera stabilization devices, automotive navigation equipment, civil and geological health monitoring, and down hole drilling systems all utilize inclinometer/ magnetometer systems. Virtual reality (VR) systems are also expected to enjoy significant market growth, for military and medical training/simulation; 3-D visualization, and 3-D video gaming. Faster, smaller, portable, and lower cost head tracking (and body segment tracking) systems are needed to meet the increasing demand for VR systems. The orientation modules produced as a result of this SBIR effort may lead to significant sales growth.